1. Field of the Invention
The invention concerns an earpiece and an ear pad for an ear canal earpiece.
2. Description of Related Art
Ear canal earpieces are also known as in-ear earpieces. Such earpieces generally have an acoustic sound transducer which is fitted into a housing which is inserted intra-aurally, that is to say into the ear canal. Frequently an ear pad is arranged around the housing so that wearing the ear canal earpiece in the ear is more pleasant for the user. Disposed on the housing is an electrical connection for a cable which carries an electrical signal to the sound transducer.
When such an ear canal earpiece is inserted into the ear canal of a user then the ear canal earpiece substantially air-tightly closes the ear canal. The sound emitted by the transducer thus passes from the ear canal earpiece by way of the ear canal to the eardrum of the user.
The frequency response of such an arrangement can be composed of the frequency response of the earpiece and the frequency response of the ear. The ear canal which is closed with the ear canal earpiece has a resonance behaviour upon excitation with a given resonance frequency. The precise position of that resonance frequency is dependent on the geometry of the ear canal, the position at which the ear canal earphone is in ear canal and also acoustic properties of the ear canal earpiece. The resonance frequency being considered can be for example approximately at 7.5 kHz. The excessive increase in the sound level, caused by the resonance behaviour, in the region of about 7.5 kHz, can have a detrimental effect on the quality of sound.
DE 10 2006 042 209 B2 discloses an earplug-like earpiece with a regulatable volume of a front chamber arranged between the loudspeaker and the housing.
DE 37 06 481 A1 discloses an earpiece.
US No 2008/0095393 A1 discloses an in-ear earpiece.
US No 2001/0050997 A1 describes an in-ear earpiece having a holding ring.
U.S. Pat. No. 4,298,087 discloses a bidirectional loudspeaker.
DE 10 2005 012 711 A1 discloses headphones.
DE 35 40 579 A1 discloses a hearing aid.
JP 08037697 A discloses a hearing aid.